This invention relates to semiconductor integrated microcircuit manufacturing and more particularly to temporarily packaging encapsulated integrated circuit dice for shipping.
Semiconductor integrated circuit chips are typically constructed en masse on a single wafer or other substrate of silicon or other semiconductor material. After the circuits are created, the wafers or substrates are split up, or xe2x80x9csingulatedxe2x80x9d, into individual integrated circuit chips or dice. Typically, each die is then individually encapsulated into integrated circuit packages which are capable of being attached to printed circuit boards. Encapsulated dice are often sold or transferred to other manufacturing sites. The encapsulated dice must therefore be shipped through the mail or by other freight means to destinations which can be cities, states or even countries apart. Freight travel often involves subjecting articles so transported to a harsh, contaminant-laden environment in terms of dirt and dust, as well as mechanical shock and vibration. This environment requires that the encapsulated dice be temporarily packaged to protect them from such exposure.
Over the years, the electronic industry has developed packages called carrier tapes which temporarily contain the dies during shipping. In general, carrier tapes that are used to transport components from a component manufacturer to a different manufacturer that assembles the components into new products are well known. For example, in the field of electronic circuit assembly, electronic components are often carried from a supply of such components to a specific location on a circuit board for attachment thereto. The components may be of several different types, including surface mount components. Particular examples include memory chips, integrated circuit chips, resistors, connectors, dual in-line processors, capacitors, gate arrays, etc. Such components are typically affixed to a circuit board that may later be incorporated into an electronic device.
Rather than manually affixing each individual electronic component to a circuit board, the electronics industry makes extensive use of robotic placement machines, sometimes known as xe2x80x9cpick-and-placexe2x80x9d machines, which grasp a component at a specific location (the supply) and place it at another specific location (the circuit board). To ensure the sustained operation of the robotic placement machine, a continuous supply of electronic components must be furnished to the machine.
One way to provide a continuous supply of electronic components to a desired location is to use a carrier tape. Conventional carrier tapes generally comprise an elongated plastic strip (often referred to as the carrier) that has a series of identical pockets formed at predetermined, uniformly spaced intervals along the length of the strip. The pockets are designed to receive an electronic component. A continuous cover (often referred to as a cover tape) is applied over the elongated strip to retain the components in the pockets. The carrier tape is fed to the robotic placement machine that strips the continuous cover tape from the carrier and removes the components from the pockets and places them onto the circuit board.
A need exists for packaging and methods for inexpensively protecting encapsulated dice during shipping from contamination and damage, as well as facilitating removal of the encapsulated dice from packaging upon reaching their destination.
The present invention provides a structure having an ultraviolet (UV) light or other electromagnetic radiation (EMR) transmissive or penetrable plate upon which has been placed a layer of UV light or other EMR-sensitive adhesive for securing the position of the encapsulated die or dice during shipping. The adhesive is sensitive to selected, predetermined wavelengths of EMR in that its adhesiveness, stickiness or coefficient of friction is alterable by exposing the adhesive to such selected wavelengths of EMR, such as UV light. Upon arrival of the structure at its destination, the adhesive is subjected to an EMR source emitting such radiation within the selected wavelengths, thereby reducing its adhesiveness, and allowing for less powerful pickup of the encapsulated dice during removal. The present invention may be embodied in the form of a tape-and-reel transport system for encapsulated dice.
According to one aspect of the invention, provided is a method method for loading, carrying and dispensing encapsulated semiconductor dice, comprising:
adhering a plurality of encapsulated dice in spaced relationship along an elongated tape element;
winding said elongated tape element on a reel;
unwinding said elongated tape element;
exposing said adhered singulated dice to EMR within a predetermined wavelength range and reducing the adherence of said adhered encapsulated dice to said tape element responsive to said EMR exposure.
Another aspect of the present invention provides a flexible carrier tape for storage and delivery of encapsulated die by an advancement mechanism, the carrier tape comprising:
a strip portion having a plurality of aligned pockets for carrying the encapsulated die, the pockets being spaced along the strip portion and having a bottom and opening through a top surface thereof; and,
an electromagnetic radiation sensitive material disposed on the bottom of the pockets for affixing the encapsulated die thereto.
Other objects and aspects of the present invention will become readily apparent to those skilled in this art from the following detailed description. The embodiments shown and described provide illustration of the best mode contemplated for carrying out the invention. The invention is capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings are to be regarded as illustrative in nature, and not as restrictive.